<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <div id="app">
        <div>
            <span>姓名:</span>
            <input type="text" v-model.trim="username" />
        </div>
        <div>
            <span>年龄:</span>
            <input type="number" v-model.number="age" />
        </div>
        <div>
            <span>性别:</span>
            <select v-model="gender">
          <option value="男">男</option>
          <option value="女">女</option>
        </select>
        </div>
        <div>
            <button @click="changeOrAdd">添加/修改</button>
        </div>
        <div>
            <table border="1" cellpadding="10" cellspacing="0">
                <tr>
                    <th>序号</th>
                    <th>姓名</th>
                    <th>年龄</th>
                    <th>性别</th>
                    <th>操作</th>
                </tr>
                <tr v-for="(item,index) in personList" :key="item.id">
                    <td>{{index+1}}</td>
                    <td>{{item.username}}</td>
                    <td>{{item.age}}</td>
                    <td>{{item.gender}}</td>
                    <td>
                        <button @click="del(item.id)">删除</button>
                        <button @click="change(index)">编辑</button>
                    </td>
                </tr>
            </table>
        </div>
    </div>
    <script src="./vue.js"></script>
    <script>
        const app = new Vue({
            el: '#app',
            data: {
                username: '',
                age: 0,
                gender: '',
                btn: 1,
                changeIndex: null,
                personList: [{
                    id: 1,
                    username: 'Tom',
                    age: 19,
                    gender: '男'
                }, {
                    id: 2,
                    username: 'Jone',
                    age: 21,
                    gender: '女'
                }]
            },
            methods: {
                changeOrAdd() {
                    if (this.btn) {
                        if (!this.username || !this.age) {
                            alert('姓名和年龄不能为空')
                            return
                        }
                        this.personList.push({
                            id: this.personList.length + 1,
                            username: this.username,
                            age: this.age,
                            gender: this.gender
                        })
                    } else {
                        this.personList.splice(this.changeIndex, 1, {
                            id: this.changeIndex + 1,
                            username: this.username,
                            age: this.age,
                            gender: this.gender
                        })
                    }
                    this.username = ''
                    this.age = 0
                    this.gender = ''
                },
                change(index) {
                    this.btn = 0
                    this.changeIndex = index
                    this.username = this.personList[index].username
                    this.age = this.personList[index].age
                    this.gender = this.personList[index].gender
                },
                del(id) {
                    this.personList = this.personList.filter(item => item.id != id)
                }
            }
        })
    </script>
</body>

</html>